ABSTRACT. Concepts are the constituents of thoughts and so are crucial to such psychological processes as categorization, inference, memory, learning, and decision-making. But the nature of concepts—the kind of things concepts are—and the constraints that govern a theory of concepts have been the subject of much debate. In this entry, we provide an overview of theories of concepts that is organized around five contentious issues: (1) the ontology of concepts, (2) the structure of concepts, (3) empiricism and nativism about concepts, (4) concepts and natural language, and (5) concepts and conceptual analysis.

Margolis, E., & Laurence, S. Concepts. In S. Stich & T. Warfield (eds.), The Stanford Encylopedia of Philosophy (Edward N. Zalta, ed.). <http://plato.stanford.edu/entries/concepts/>.This entry was first published in 2005 but is continually revised and updated. The last major revision was in 2011.